Holder for pyrotechnical delay composition

ABSTRACT

An annular base member of U-shaped cross section defines a recess which is at least partially filled with a gasless, combustible pyrotechnical delay composition. The recess and base member are covered by an opposing annular covering member of Ushaped cross section in pressure engagement with a deformable ring positioned between the interior base of the covering member and the upper surface of the delay composition which yields to fill any unfilled portions of the recess and to conform with the upper surface of the delay composition. An actuatable device adapted to respond to combustion of the delay composition is located adjacent the composition at a predetermined position. The covering member is provided with a plurality of spaced holes, a selected one of which receives an ignition device operative to ignite the delay composition at a position spaced from the actuatable device, and a barrier structure is disposed within the composition to assure that combustion of the delay composition thereafter propagates to the actuatable device in a single direction only, thereby to achieve an accurate time delay between operation of the ignition device and subsequent operation of the actuatable device.

United States Patent [1 1 Simmons Nov. 26, 1974 HOLDER FOR PYROTECHNICALDELAY [57] ABSTRACT COMPOSITION An annular base member of U-shaped crosssection [75] Inventor: Bjiirn Herman Olof Simmons, defines a recesswhich is at least partially filled with a Karlskoga, Sweden gasless,combustible pyrotechnicall delay composition. [73] AssigneeZ AB BoforsBofors Sweden The recess and base member are covered by an opposingannular covering member of U-shaped cross secl Filed! 1973 tion inpressure engagement with a deformable ring positioned between theinterior base of the covering [21] Appl' 346537 member and the uppersurface of the delay composition which yields to fill any unfilledportions of the rel Foreign Application Priority Data cess and toconform with the upper surface of the Apr. 14, 1972 Sweden 4865/72 delaycomposition. An actuatable device adapted to respond to combustion ofthe delay composition is 10- [52] us. Cl. 102/s5.2, 102/86.5 Gatedadjacent the composition at a predetermined 51 Int. Cl. F42c 9/10position. The covering member is provided with a p [58] Field of Se h102/27, 39, 70, 72 85 rality of spaced holes, a selected one of whichreceives 102/85.2, 85.6, 86.5; 89/1 B an ignition device operative toignite the delay composition at a position spaced from the actuatabledevice, [5 6] R f Cit d and a barrier structure is disposed within thecomposi- UNITED STATES PATENTS tion to assure that combustion of thedelay composi- 729 932 6/1903 Hathawa 10w 2 tion thereafter propagatesto the actuatable device in M98544 9/1916 Loomis 1O2/85:2 a singledirection only, thereby to achieve an accurate 1,318,720 10/1919 Bergman102/85 2 time delay between operation of the ignition device 1,508,450 91924 Goss 102 s5.2 and Subsequent Operation of the actuatable device2,583,802 1/1952 Wright et al... 102/70 2,869,463 1/1959 McKnight 102/393,170,365 2/1965 Vaughn 89/1 B Primary ExaminerVerlin R. PendegrassAttorney, Agent, or Firm--Elliott Pollock 9 Claims, 4 Drawing FiguresPATENTE; 53V 28 I974 SHEET 10F 2 PATENIEUISVZSIHM 1850,10;

SECTION AA Fig 3 SECTION B Fig 4 HOLDER FOR PYROTECHNICAL DELAYCOMPOSITION BACKGROUND OF THE INVENTION In FIG. 1, the referencedesignation 1 is a base part The present invention relates to a holderfor a subhich as the form Of an nner ring which has a substantiallygasless, combustible pyrotechnical delay composition comprising a basepart with a channel-like recess in which the base part supports thecomposition and a covering part applied to the base part and coveringthe recess, the base part and/or the covering part having holes adaptedto receive an ignition device for the composition or an actuatabledevice which can be initiated by the composition.

These delay compositions are primarily of the kind utilized forprojectiles, bombs, rockets etc. in which the delay composition, at apredetermined time after the firing, is to cause initiation of someevent. In order to obtain minimum variation between different specimensof the type of ammunition in question, it is of essential importancethat the delay composition work with great accuracy as regards the timedelay provided thereby.

The actual delay composition can consist of a composition which is knownin itself, and which comprises an oxygen producer and an oxygenabsorber. The com position burns substantially gaslessly and in aglowing fashion.

The present invention constitutes an improved holder for a delaycomposition of the aforementioned kind which permits the composition,with regard to the time aspect, to function with an accuracy which hasbeen impossible to attain with hitherto known devices. The property thatcan mainly be considered to characterize a holder according to theinvention is that, between the base part and the part covering saidrecess, an element made of lead or other viscous-elastic material withcorresponding properties is applied, and the base part and the coveringpart are affixed to each other under a pressure which acts upon theelement and the composition, and which causes the material in theelement to yield, whereby the element adapts itself to the composition,regardless of the extent to which the composition fills up the recess.

As a result of the foregoing considerations, the composition isprestressed along its entire extent even if the composition is notuniformly distributed in the recess, and the composition will also bewell enclosed and can burn evenly and without expansion, whichguarantees that the composition can function with the great accuracydesired, without any extremely severe requirements having tobe placed onthe correct extent of the filling of the composition in the recess.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment presently proposed whichhas the foregoing characteristics will be described in more detail inthe following, with reference to the attached drawings, in which FIG. 1shows a vertical view in cross-section of a holder with a delaycomposition therein,

FIG. 2 is a horizontal view partly in cross-section of the holder shownin FIG. 1,

FIG. 3 is a vertical view and a cross-section taken on section (A-A) ofFIG. 2, and

FIG. 4 shows a vertical view and a cross-section taken on section (B-B)of FIG. 2.

stantially U-shaped cross-section, the legs of the U- shape enclosing achannel-like recess, in which a delay composition 2 is disposed. As thecomposition itself does not concern the present invention, thecomposition will not be discussed in detail in the present application.Onto the base part and covering said recess a covering part 3 isapplied, which has the form of an outer ring, which also has a U-shapedcross-section. This second ring is placed on top of the first ring inopposing relation thereto, and the legs in the respective U-shapes thenextend past each other.

Between the base part I and the covering part 3, over said recess andcomposition 2, there is located an element 4, of lead, which in theexample of the embodiment is a ring-shaped washer. Said washer 4 is incontact with the base part 1, at the end surfaces of the legs of thebase part 1, and is in contact with the upper surface of thecomposition. The washer 4 is also in contact with the covering part atthe inner bottom surface of this part. The base part 1 and the coveringpart 3 are affixed to each other under a pressure which acts upon theelement 4 and therewith upon the composition 2, and the pressure is ofsuch a magnitude that it causes the material in the element 4 to yield,so that it adapts itself into surface conformity with the composition,regardless of the extent to which the composition fills up the recess inbase part 1. The filling can be uneven along the extent of thecomposition, which is illustrated in FIG. 1, by a recess formed in thewasher 4 in the left cross-section, while in the right cross-section aprotrusion has been formed in the washer 4.

Said pressure is achieved by the outer sections 3a of the legs of theouter ring 3, being folded over obliquely chamfered surfaces Ia of theinner ring 1 at the time of manufacture. The material in the parts 1 and3 can be chosen to conform to what is customary in this respect. As analternative to fabricating the element 4 of lead, a material or an alloycan be chosen which has a viscous-elasticity at temperatures around roomtemperatures, and which does not participate in the combustion of thecomposition.

FIG. 2 illustrates more conspicuously the function of the holder withthe delay composition. The composi- ,tion 2, which extendscylindrically, is provided with a barrier member 5, which assures thatan actuatable device 6 that can be operated by combustion of thecomposition 2 can be reached only from one combustion direction of thecomposition, relative to the position at which an ignition device 7 isfastened. To an extent corresponding to the extent of the composition,the base of covering part 3 is provided with holes 8, spaced in acertain way and extending from the outside in towards the delaycomposition 2. The ignition device 7 can be placed arbitrarily in any ofthe holes 8, each of which represents a specific delay time for whichthe composition is to act. After ignition has taken place at theignition device 7, the composition will burn in both the clockwise andthe anti-clockwise directions from the device 7. Due to the barriermember 5, however, the actuatable device 6 will be actuated only fromthe clockwise direction.

ignition composition 9 and a flash Composition 10. The

flash composition 10 is in contact with the delay comv position 2 via achannel 11, which is-formed by both said holes in the first part andholes in the element 4. The friction ignition composition 9 is initiatedby a symbolically drawn striker pin 12, which via a spring 13 is appliedto the friction ignition composition 9 by an acceleration that takesplace in the projectile or corresponding object in which it is assumedthat the delay composition is applied. The striker pin 12 can beincluded in devices of various kinds which are actuated byaccelerations; thus, these need not be described here. The frictionignition composition 9 and the flash composition 10 function in wayswhich are known in themselves.

FIG. 4 illustrates an actuatable device 6, which can be initiated by thedelay composition 2, taking the form of a powder pellet (flash type)disposed in a hole within the base part 1. When the delay composition 2has ignited the powder pellet 6, this in turn usually sets off aninitiating composition 15 of some kind, which is indicated symbolicallyby broken lines. The initiating composition 15 can consist of blackpowder, and for example for illuminating ammunition can be utilized forseparation of the shell, ignition of the flare etc.

The invention is not limited to the embodiment shown as an example, butcan be subject to modifications within the scope of the followingclaims. Thus, the delay composition need not be circular.

I claim:

, l. A holder for a pyrotechnical delay composition comprising a basepart having a channel-shaped recess, a gasless combustible pyrotechnicaldelay composition disposed within said recess, a covering part affixedto said base part in covering relation to said recess, at least oneof'said parts including a plurality of holes therein a selected one ofwhich is adapted to receive a device operative to cooperate with saidcomposition, and a deformable member fabricated of a material which isincapable of participating in the combustion of said delay composition,said deformable member being disposed between said base part and saidcovering part in contiguous relation to the upper surface of saidcomposition, said base part and covering part being attached to oneanother in pressure engagement with said deformable member, the pressureimposed on said deformable member being operative to cause said materialto deform into close surface conformity with the upper surface of saidcomposition entirely across said recess regardless of the extent towhich said composition fills said recess.

2. The holder of claim 1 wherein said deformable member is fabricated oflead.

3. The holder of claim 1 wherein saidbase part, said covering part, andsaid deformable member are each ring-shaped.

4. The structure of claim 1 wherein said device com prises an ignitiondevice.

5. The structure of claim 1 wherein said device comprises an actuatabledevice operative to be actuated in response to ignition of saidcomposition.

6. The structure of claim 1 wherein said base part and recess are eachof circular configuration, said holes being positioned along asubstantially circular locus in said covering part, an actuatable devicedisposed at a predetermined location adjacent said composition andoperative to be actuated by burning of said composition adjacent saidpredetermined location, an ignition device disposed in a selected one ofsaid holes at a position angularly spaced from said actuatable devicefor initiating ignition of said composition at said spaced position toeffect propagation of combustion along a circular path toward saidactuatable device thereby to effect a delay time between operation ofsaid ignition device and operation of said actuatable device dependentupon the angular spacing between said two devices, and a barrier memberdisposed within said composition for restricting the direction ofcircular propagation of combustion from said ignition device to saidactuatable device.

7. The structure of claim 6 wherein said actuatable device is alsodisposed in one of said holes.

8. The structure of claim 1 wherein said base part comprises an innerring-shaped member of substan tially U-shaped cross section, said recessbeing defined between the legs of said inner member, said deformablemember being annular in shape and being positioned to overlie and engagethe free ends of the legs of said inner ring-shaped member in coveringrelation to said recess, said covering part comprising an outerringshaped member of U-shaped cross section the legs of which aredisposed exterior to, and extend in the direction opposite to, the legsof said inner ring-shaped member.

9. The structure of claim 8 wherein the exterior of said innerring-shaped member is provided with obliquely champhered surfacesadjacent the base of its U-shaped cross section, the free ends of thelegs of said outer ring-shaped member being bent over said champheredsurfaces to effect firm engagement between said inner and outer ringsand pressure engagement with said deformable annulus.

1. A holder for a pyrotechnical delay composition comprising a base parthaving a channel-shaped recess, a gasless combustible pyrotechnicaldelay composition disposed within said recess, a covering part affixedto said base part in covering relation to said recess, at least one ofsaid parts including a plurality of holes therein a selected one ofwhich is adapted to receive a device operative to cooperate with saidcomposition, and a deformable member fabricated of a material which isincapable of participating in the combustion of said delay composition,said deformable member being disposed between said base part and saidcovering part in contiguous relation to the upper surface of saidcomposition, said base part and covering part being attached to oneanother in pressure engagement with said deformable member, the pressureimposed on said deformable member being operative to cause said materialto deform into close surface conformity with the upper surface of saidcomposition entirely across said recess regardless of the extent towhich said composition fills said recess.
 2. The holder of claim 1wherein said deformable member is fabricated of lead.
 3. The holder ofclaim 1 wherein said base part, said covering part, and said deformablemember are each ring-shaped.
 4. The structure of claim 1 wherein saiddevice comprises an ignition device.
 5. The structure of claim 1 whereinsaid device comprises an actuatable device operative to be actuated inresponse to ignition of said composition.
 6. The structure of claim 1wherein said base part and recess are each of circular configuration,said holes being positioned along a substantially circular locus in saidcovering part, an actuatable device disposed at a predetermined locationadjacent said composition and operative to be actuated by burning ofsaid composition adjacent said predetermined location, an ignitiondevice disposed in a selected one of said holes at a position angularlyspaced from said actuatable device for initiating ignition of saidcomposition at said spaced posItion to effect propagation of combustionalong a circular path toward said actuatable device thereby to effect adelay time between operation of said ignition device and operation ofsaid actuatable device dependent upon the angular spacing between saidtwo devices, and a barrier member disposed within said composition forrestricting the direction of circular propagation of combustion fromsaid ignition device to said actuatable device.
 7. The structure ofclaim 6 wherein said actuatable device is also disposed in one of saidholes.
 8. The structure of claim 1 wherein said base part comprises aninner ring-shaped member of substantially U-shaped cross section, saidrecess being defined between the legs of said inner member, saiddeformable member being annular in shape and being positioned to overlieand engage the free ends of the legs of said inner ring-shaped member incovering relation to said recess, said covering part comprising an outerring-shaped member of U-shaped cross section the legs of which aredisposed exterior to, and extend in the direction opposite to, the legsof said inner ring-shaped member.
 9. The structure of claim 8 whereinthe exterior of said inner ring-shaped member is provided with obliquelychamphered surfaces adjacent the base of its U-shaped cross section, thefree ends of the legs of said outer ring-shaped member being bent oversaid champhered surfaces to effect firm engagement between said innerand outer rings and pressure engagement with said deformable annulus.